Picked up the hero 3 black for an upcoming trip, and got the wasabi extra batteries and charger. Debating whether or not to get the battery bacpac (like the thinness/lightness of the hero3 without it). How long realistically do you think I'll get on a charge shooting 720p/60 with wifi disabled? Temperate to cool weather (motorcycle riding in japan mostly)

My Hero 3 battery life is nothing to brag about... I get an hour and a half tops with wifi on, no backpack. Wifi off it's more like 3, but I really enjoying the wifi because I can control with my phone easily.